Fastening device for a heat exchanger unit and vehicle equipped with a heat exchanger unit

ABSTRACT

A fastening device for a heat exchanger unit ( 10 ) on a vehicle comprises, on each side of the vehicle, an upper and a lower fastening point ( 15,   16 ). The heat exchanger unit ( 10 ) is, via the fastening points ( 15, 16 ), fastened on both sides at least indirectly to the vehicle frame. To this end, a retaining bracket ( 11 ) is provided that joins the upper and lower fastening points ( 15, 16 ) to one another, this retaining bracket ( 11 ) being able to be fastened at least indirectly to the vehicle frame longitudinal member. The heat exchanger unit ( 10 ) is only fastened to deformation elements ( 12 ) that join the members ( 13 ) subject to bending to the frame longitudinal members ( 14 ) of the vehicle.

Vehicles, especially motor vehicles, usually have a heat exchanger unit which is arranged in the front region of the vehicle, in particular behind a radiator grill, but still in front of the drive assembly of the vehicle. The heat exchanger unit is in this case held, in particular, indirectly on the vehicle frame. The vehicle frame is in this case normally formed by a longitudinal member on each vehicle side and a bending member connecting these two longitudinal members.

As seen in the direction of travel of the vehicle, the bending member lies in front of such a heat exchanger unit which serves, for example, for the cooling of operating media, such as cooling water, refrigerant and engine/transmission oil, by ambient air flowing through. The bending member serves, in the event of collisions, for the introduction of loads into the longitudinal members of the vehicle and for distributing the load arising to the two vehicle sides, deformation elements being arranged between the bending member and the longitudinal member.

The heat exchanger unit in this case has upper and lower fastening points on both vehicle sides in order to be held securely in the vehicle. The lower fastening points typically lie level with the longitudinal members and the upper fastening points in the region of what is known as the locking crossmember which is itself supported on the bending member and on the vehicle longitudinal members and runs above the bending member in the vehicle transverse direction.

It conforms in this case to a conventional design when deformation elements prolonging the longitudinal members are provided between the longitudinal member and bending member and, in the event of collisions, are deformed plastically in a predetermined way and at the same time break down energy. In addition to the breakdown of energy, a deformation of the longitudinal members in the event of a collision is avoided up to a certain degree of energy introduced, so that the damage which arises can be repaired more easily and more cost-effectively.

In a collision in which the deformation elements are deformed, the heat exchanger unit is to remain as intact as possible in order to maintain the driveability of the vehicle and to minimize repair costs.

The object of the invention is to provide, for a heat exchanger unit, a fastening possibility which as largely as possible affords this intactness of the heat exchanger unit even when the free space between the bending member and the engine arranged between the longitudinal members is small.

This object is achieved by means of a fastening device according to the invention and by means of a vehicle designed according to the invention.

A fastening device for a heat exchanger unit on a vehicle has an upper and a lower fastening point on each vehicle side. The heat exchanger unit is fastened at least indirectly to the vehicle frame on both sides by the fastening points. In this case, according to the invention, a holding bracket is provided, which connects the upper and the lower fastening point to one another, the holding bracket being fastenable at least indirectly to the vehicle longitudinal member.

The holding bracket affords a fastening device which, in the same way as a frame part running in the vertical direction, makes it possible to fasten the heat exchanger unit at only one location on each vehicle side. As a result, the mounting of the heat exchanger unit is independent of the different fastening on the upper and lower front region (locking crossmember or bending member) and can also be comoved with a displacement of the fastening location on the longitudinal member or the deformation elements. The heat exchanger unit therefore remains undamaged over a larger range.

A holding bracket is therefore to be provided on each vehicle side, and it is provided in each case on that edge region of the heat exchanger unit which lies in the vehicle transverse direction. In order to ensure a reliable mounting of the heat exchanger unit in the vertical direction, there is in this case preferably provision for the holding bracket to extend vertically over a large region of the heat exchanger. The at least indirect fastening of the holding bracket to the vehicle longitudinal member is in this case to be designed such that a tilting of the holding bracket is prevented. This may take place, in particular, by means of two fastening points spaced vertically apart from one another.

It conforms in this case to an advantageous refinement of the fastening device if vibration dampers are provided at the upper and the lower fastening point between the holding bracket and the heat exchanger unit. This in each case affords a shock-absorbing mounting which is suitable for absorbing load peaks. By contrast, the connection between the holding bracket and deformation element is preferably made rigidly.

According to an advantageous refinement of the fastening device, there is provision for the holding bracket to project out of the connecting plane of the fastening points in the vehicle longitudinal direction. As a result, on the one hand, a secure holding of the heat exchanger unit is afforded and, on the other hand, the positioning of the heat exchanger unit can be offset in the vehicle longitudinal direction via this distance, due to a corresponding configuration of the holding bracket, from the fastening location on the longitudinal member. This affords the possibility of a position of the heat exchanger unit in the vehicle longitudinal direction which is more favorable in collision and functional terms, for example with a greater distance between the heat exchanger unit and the drive assembly lying behind it. For this purpose, the holding bracket is preferably of essentially D-shaped design. In this case, the holding bracket forms the bent portion of the imaginary D, while the heat exchanger unit forms the linear back.

A vehicle has a vehicle frame with longitudinal members spaced apart from one another and with a bending member which connects the longitudinal members to one another in the transverse direction and runs in front of the longitudinal members. Deformation elements are arranged between the longitudinal member and bending member. A heat exchanger unit is supported on the vehicle frame. According to the invention, there is provision for the heat exchanger unit to be fastened only to the deformation elements and, via these, indirectly to the longitudinal member.

By virtue of this measure, particularly in the event of an offset frontal collision, a different force is introduced to the longitudinal members on the two sides of the vehicle, and a displacement of the position of the heat exchanger unit with the deformation of the front region of the vehicle is made possible. As a result, the heat exchanger unit remains, over greater load ranges, without contact with the drive assembly lying behind it. On account of this, damage to the heat exchanger unit is avoided, repair costs are reduced and a driveability of the vehicle may possibly still be maintained. It is important, for this purpose, that the fastening takes place only via the deformation elements, and that further fastening locations are not provided on the upper vehicle region, so that the displacement of the heat exchanger unit in the vertical direction is counteracted in the event of a collision. At the same time, this ensures that the bending member and the heat exchanger unit do not come into contact with one another in the deformation region of the deformation element in the event of a collision. Damage to the heat exchanger unit by the bending member is thereby avoided in this region. Finally, this type of design makes it possible to arrange the heat exchanger unit further forward, nearer to the bending member, and thereby to gain greater free space behind the heat exchanger.

It conforms in this case to an advantageous refinement if the fastening location of the heat exchanger unit on the deformation element is selected in such a way that the heat exchanger unit remains free of damage in the event of maximum deformation of the deformation element. This ensures that, in the event of a collision, the energy of which is so low that only a deformation of the deformation element takes place, the heat exchanger unit is comoved only with the deformation element and the fastening point which is displaced, without damage to the heat exchanger unit, for example due to contact with the drive assembly lying behind it or with its secondary assemblies, occurring.

This is achieved in a particularly advantageous way in that a free space is formed between the heat exchanger unit and the assemblies lying behind it, the heat exchanger unit being displaced rearward by the amount of no more than the free space in the event of a maximum deformation of the deformation element. The position of the fastening point of the heat exchanger unit on the deformation element is therefore selected such that, in the event of a maximum deformation of the deformation element, contact between the heat exchanger unit and the assemblies lying behind it is still just avoided. At the same time, contact between the bending member and heat exchanger unit is then also avoided. The heat exchanger unit remains intact.

It conforms to an advantageous refinement if at least one of the elements comprising the bending member and the deformation elements has in each case at least one flange for fastening to one another, the heat exchanger unit being fastened to these flanges. These flanges are in any case to be provided and afford the possibility in a simple way of providing fastening points of the heat exchanger unit. In this case, according to the invention, fastening may take place on flanges located on the bending member side.

According to an advantageous refinement, there is provision for the heat exchanger unit to be fastened to the deformation elements, in each case a fastening location for the heat exchanger unit being formed in a deformation region. This constitutes an alternative to fastening to the connecting flanges between the deformation element and the bending member.

According to further advantageous refinements, holding brackets according to the invention are provided on both sides for fastening the heat exchanger unit. The fastening, defined in the vertical direction, of the heat exchanger unit is thereby made possible in a particularly beneficial way.

Moreover, the invention is explained in more detail below with reference to the embodiment illustrated in the drawing in which:

FIG. 1 shows a diagrammatic cross-sectional drawing of a vehicle front region;

FIG. 2 a, 2 b show the top view of the fastening of the heat exchanger unit according to FIG. 1 on a vehicle side before and after a collision; and

FIG. 3 shows the cross-sectional illustration of FIG. 1 in two separate part drawings.

FIG. 1 shows a diagrammatic partly sectional side view of the heat exchanger unit 10 which is fastened to the deformation element 12 via the holding bracket 11. The deformation element 12 extends as far as the bending member 13. In this case, the deformation element 12 projects axially forward from the longitudinal member 14 in the vehicle longitudinal direction. The corresponding top view is shown in FIG. 2 a and 2 b. FIG. 3 shows the view of FIG. 1 in two separate part figures, the upper figure half showing the situation before a collision and the lower figure half showing the situation after a collision.

In this case, the holding bracket 11 extends in the vertical direction and connects the upper fastening points 15 and the lower fastening points 16 of the heat exchanger unit to one another. At each of these fastening points, a rubber buffer 17 is provided between a fastening sleeve 18 located on the holding arm side and a fastening dowel 19 located on the heat exchanger side. The holding arm 11 extends arcuately between the upper and the lower fastening point 15, 16. The fastening dowels 19 of the heat exchanger unit and of the upper and the lower fastening point 15 and 16 are in this case oriented at right angles to one another, one in the vertical direction and the other in the transverse direction of the vehicle. As a result, on the one hand, the position of the heat exchanger can be adjusted and tolerance compensation is possible and, on the other hand, a stable mounting is afforded in both directions. The heat exchanger unit 10 is of essentially self-supporting design, but may have a lateral auxiliary frame which serves for connecting different part elements of the heat exchanger unit to one another. Such an auxiliary frame then preferably extends over both fastening points 15 and 16 of a vehicle side, and it may, furthermore, surround the heat exchanger unit 10 on all sides (transverse direction and vertical direction).

In the region furthest away from the heat exchanger unit in the vehicle longitudinal direction, the holding bracket 11 is fastened to the deformation element 12 at two adjacent connecting locations 20 provided vertically one above the other. In this case, in the region of the deformation element 12, a fastening region 22 is formed which can be seen more clearly in the top view in FIG. 2 a, 2 b. Rubber buffers 17 may in each case likewise be provided at the fastening locations 20.

The holding bracket 11 with the connecting locations 20 and the heat exchanger unit 10 with its fastening points 15, 16 provide a fastening device for the heat exchanger unit 10. By means of this fastening device, the heat exchanger is held solely on the deformation elements 12. A vehicle with a corresponding fastening of the heat exchanger unit 10 solely to the deformation element 12 of the longitudinal member 14 is produced.

The fastening on the fastening region 22 of the deformation element 12 may be replaced by the fastening on the connecting flange between the deformation element 12 and bending member 13. The connecting flange may in this case be formed both on the bending member side and on the deformation element side.

FIG. 1 and FIGS. 2 a, 2 b show the position of the bending member 13 and of the heat exchanger unit 10 before (FIG. 2 a) and after (FIG. 2 b) a collision in which the deformation element has been deformed plastically by being folded up in a concertina-like manner. X and Y designate the displacement travels of the bending member 13 and heat exchanger unit 10 which can be achieved without damage to the longitudinal member 14 and heat exchanger unit 10. Owing to the plastic deformation of the deformation element 12, collision energy is in this case absorbed and nullified. FIG. 1 illustrates the situation before the collision more thinly than after the collision, of the initial position before the collision only the holding arm 11 being shown, and the heat exchanger unit 10 being illustrated only in the end position after the deformation of the deformation element 12. FIG. 2 a shows the top view before a collision and FIG. 2 b a top view after the collision. By being mounted in this way, the heat exchanger acquires substantial protection against damage in the event of collisions. Owing to the possibility of displacing the heat exchanger with the folding up of the deformation element 12, what is achieved, furthermore, is that more space between the heat exchanger and engine is present and consequently a better flow through the heat exchanger becomes possible.

FIG. 3 shows the view of FIG. 1 in two separate part figures, the upper figure half showing the situation before a collision and the lower figure half showing the situation after a collision. In this case, it is clear particularly well from a comparison of the figure halves that the position of the heat exchanger unit 10 is shifted rearward by the amount of the displacement travel X during the deformation of the deformation elements 12. The position of the bending member 13 changes in this case by the amount of the displacement travel Y which is correspondingly greater. The ratio of the displacement travels X and Y to one another is in this case dependent on the position of the fastening region 22 and the deformation element 12 and is determined according to the space conditions in the vehicle. The illustration of FIG. 3 otherwise corresponds to that of FIG. 1, and therefore reference is made to the relevant description. 

1. A fastening device for a heat exchanger unit on a vehicle, the heat exchanger unit having at least one fastening point and being fastened at least indirectly to the vehicle frame via the at least one fastening point, wherein the heat exchanger unit is fastened to a deformation element of the vehicle frame.
 2. A fastening device for a heat exchanger unit on a vehicle, the heat exchanger unit having a first and a second fastening point and being fastened at least indirectly to the vehicle frame via the fastening points wherein a holding bracket is provided which connects the first and the second fastening point to one another, the holding bracket being fastenable at least indirectly to the vehicle longitudinal member.
 3. The fastening device as claimed in claim 2, wherein at least one vibration damper is provided at the at least the first or the second, fastening point between a holding element and the heat exchanger unit.
 4. The fastening device as claimed in claim 2, wherein the holding bracket projects out of the connecting plane of the fastening points in the vehicle longitudinal direction and can be fastened vertically at two adjacent fastening locations lying one above the other.
 5. The fastening device as claimed in claim 4, wherein the holding bracket is of essentially D-shaped design.
 6. A heat exchanger device with at least one heat exchanger, preferably a plurality of heat exchangers, having a fastening device as claimed in claim
 1. 7. A vehicle with a vehicle frame with longitudinal members spaced apart from one another and with a bending member which connects the longitudinal members to one another in the transverse direction and runs in front of the longitudinal members, with deformation elements arranged between the longitudinal member and bending member, and with a heat exchanger unit fastened to the vehicle frame, wherein the heat exchanger unit is fastened only to the deformation elements.
 8. The vehicle as claimed in claim 7, wherein the fastening location of the heat exchanger unit on the deformation element is selected in such a way that the heat exchanger unit remains free of damage in the event of a maximum deformation of the deformation element.
 9. The vehicle as claimed in claim 8, wherein a free space is formed between the heat exchanger unit and the assembly lying behind it, the heat exchanger unit being displaced rearward by the amount of no more than the free space in the event of a maximum deformation of the deformation element.
 10. The vehicle as claimed in claim 7, wherein at least one of the elements comprising the bending member and the deformation elements has in each case at least one flange for fastening to one another, the heat exchanger unit being fastened to one of these flanges.
 11. The vehicle as claimed in claim 10, wherein the heat exchanger unit is held on the fastening flange of the bending member.
 12. The vehicle as claimed in claim 7, wherein the heat exchanger unit is fastened to the deformation elements a fastening location for the heat exchanger unit being formed on the deformation elements.
 13. The vehicle as claimed in claim 7, wherein the heat exchanger unit is fastened by means of a holding bracket, the holding bracket being designed so that the heat exchanger unit has at least one fastening point and is fastened at least indirectly to the vehicle frame via the at least one fastening point.
 14. The vehicle as claimed in claim 7, wherein the heat exchanger unit is fastened by means of a holding bracket, the heat exchanger unit having a first and a second fastening point and being fastened at least indirectly to the vehicle frame via the fastening points, wherein the holding bracket connects the first and the second fastening point to one another, the holding bracket being fastened at least indirectly to the vehicle longitudinal member.
 15. The vehicle as claimed in claim 14, wherein at least one vibration damper is provided at the at least the first or the second fastening point between a holding element and the heat exchanger unit.
 16. The vehicle as claimed in claim 14, wherein the holding bracket projects out of the connecting plane of the fastening points in the vehicle longitudinal direction and can be fastened vertically at two adjacent fastening locations lying one above the other.
 17. The vehicle as claimed in claim 16, wherein the holding bracket is of essentially D-shaped design. 